Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/07/19
Area Forecast Discussion
National Weather Service Bismarck ND
912 PM CDT Sat Apr 6 2019
.UPDATE...
Issued at 910 PM CDT Sat Apr 6 2019
Dense fog has spread further west this evening, with webcam and
surface weather observations showing dense fog across most of
central North Dakota and parts of northwest North Dakota.
Therefore, the Dense Fog Advisory has been expanded to include all
of central North Dakota, and portions of northwest North Dakota.
UPDATE Issued at 846 PM CDT Sat Apr 6 2019
Dense fog has returned across portions of north central North
Dakota this evening. Visibilities of 1/4 mile or less are being
reported. The latest CAM model guidance has dense fog remaining
through the night. Therefore, the Dense Fog Advisory has been
expanded to include Rolette and Pierce counties.
UPDATE Issued at 525 PM CDT Sat Apr 6 2019
Observed temperatures across south central North Dakota have been
about 5 to 10 degrees warmer than the forecast highs for today.
The latest observations were blended in to adjust the forecast
highs. The rest of the forecast remains well on track. Used the
latest iteration of the RAP13 to populate the probability of fog
this evening through tomorrow morning, which did not change the
previous fog forecast by much. Still monitoring southwest North
Dakota for the possible development of convection this evening as
a warm front pushes through. CAM model guidance has been
overdoing thunderstorm development thus far, as convection has yet
to be observed across the southwest.
&&
.SHORT TERM...(This afternoon through Sunday)
Issued at 254 PM CDT Sat Apr 6 2019
A very moist boundary layer with easterly upslope flow has sustained
fog, dense at times, across much of the state into this afternoon.
The fog and low clouds have started to erode in far southwest North
Dakota, where low-level flow is beginning to turn westerly. The
expectation is for the fog and low stratus to persist where flow
remains easterly. Winds will begin switching to westerly from west
to east overnight as a surface trough moves through. The Dense Fog
Advisory is scheduled to remain in effect for counties east of the
Missouri River and south of Highway 2 until 10 AM CDT Sunday.
Scattered showers tied to a mid-level disturbance continue across
northwest into far north central North Dakota this afternoon.
Further development tied to this wave cannot be ruled out farther
south. Off to the west, isolated to scattered showers and
thunderstorms are forecast to develop by early evening along the
aforementioned surface trough across far western North Dakota.
Forcing for ascent may be aided by frontogenetical forcing resultant
from strong diurnal heating to the west of the surface trough and
low-level clouds. Multiple runs of the RAP have indicated the
potential for up to 1000 J/kg of CAPE over southwest North Dakota.
Deep layer shear may approach 30 kts, but this is in part due to low-
level flow being relatively weak. Given cold temperatures aloft,
would not be surprised to see small hail with any storm that
develops. This convection should dissipate overnight as it moves
eastward into more stable air. Additional showers and isolated
storms may develop back over southwest North Dakota overnight as a
mid-level shortwave moves through.
Behind the mid-level shortwave, skies should clear with increasing
westerly winds on Sunday. Will need to monitor fire weather
conditions across western North Dakota Sunday afternoon as highs
reach well into the 60s and winds gust near 35 mph.
.LONG TERM...(Sunday night through Saturday)
Issued at 254 PM CDT Sat Apr 6 2019
A mid-level disturbance will bring a slight chance of rain across
the state Sunday night into Monday morning, with upper-level ridging
building in behind into Tuesday. Temperatures will remain above
normal Monday.
A strong low pressure system is forecast to move off the Rockies
into the Central Plains mid week. While the existence of this storm
has been consistent in guidance, its track and strength have greatly
varied from model-to-model and run-to-run. Long-range ensembles
continue to show significant spread. If this storm system takes a
more southerly track (12Z ECMWF), much of North Dakota could remain
dry. If it takes a more northerly track (12Z GFS), impactful winter
weather cannot be ruled out across southern North Dakota. Regardless
of the storm track, temperatures are looking to trend below normal
mid to late week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 654 PM CDT Sat Apr 6 2019
Fog will continue to affect KBIS, KMOT, and KJMS this evening
through mid-morning tomorrow. The fog will be dense at times,
falling to 1/4 mile or less. In addition, a stray rain shower or
thunderstorm is possible tonight. Any shower or thunderstorm looks
to be isolated and short-lived. Fog and low clouds will gradually
push eastward tomorrow morning, giving way to mostly sunny skies
and gusty winds for the afternoon hours.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM CDT /9 AM MDT/ Sunday for
NDZ002>005-010>013-019>023-025-034>037-042-045>048-050-051.
&&
$$
UPDATE...TK
SHORT TERM...Hollan
LONG TERM...Hollan
AVIATION...TK
Area Forecast Discussion
National Weather Service Columbia SC
815 PM EDT Sat Apr 6 2019
.SYNOPSIS...
A warm front will lift northward over the forecast area Sunday
bringing a chance for showers and thunderstorms. A low pressure
system will then move across the Deep South early next week
resulting in numerous showers and thunderstorms Monday and
Tuesday. Dry weather is expected Wednesday and Thursday with the
next frontal system approaching the area late in the week.
Temperatures near or above normal are expected over the next 7
days.
&&
.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
Showers in the southern Midlands and CSRA have moved east of the
area or dissipated with the frontal boundary remaining south of
the area. Overnight the frontal boundary will slowly move
northward with the main concern being a large thunderstorm
complex currently in MS. The thunderstorms are expected to move
northeastward and slowly weaken however the HRRR maintains the
storms will reach the Upstate. As such have maintained a dry
forecast for much of the overnight with slight chance of showers
toward daybreak as the frontal boundary moves into the Midlands
along with potential instability associated with convection in
the Upstate. Patchy fog may develop along and north front where
upper level dry air possible to enhance nocturnal cooling.
Overnight lows will be in the upper 50s to low 60s.
&&
.SHORT TERM /7 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
Sunday and Sunday night: A warm front will lift northward through
the CSRA and Midlands during the day. Convection should develop
along the lifting front but widespread showers are unlikely.
With increasing moisture and instability through the afternoon,
there will be a better chance of some thunderstorm development.
20 kt deep-layer shear values and weak to moderate instability
suggest pulse-type thunderstorms or multi-cell clusters. A near
saturated vertical profile and PWAT values at 1.5 inches or
less limits the threat of downburst winds and heavy rain.
Convective activity should diminish after loss of daytime
heating but a few isolated showers will still be possible
overnight. Temperatures will be above normal with max temps in
the middle 70s to lower 80s, and overnight lows in the 60s.
Monday and Monday night: Mid-level ridging pushes eastward
allowing for warm, moist advection to develop in SW flow.
Scattered convection should develop during the day in a
moderately sheared environment. Outflow from convection that
develops upstream may allow for a more organized thunderstorm
system to push into the area late in the day or evening. This
pattern supports a likely to categorical (55% or higher) chance
of rain during the period. Temperatures will be warm through the
day with highs around 80, and overnight lows Monday night in
the 60s.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
An upper level low and associated surface low will move through
the Southeast on Tuesday/Tuesday night. Showers and possibly
thunderstorms should continue through much of Tuesday,
diminishing overnight as the trough and deepest moisture moves
eastward. Drier conditions return to the Southeast by midweek
with above normal temperatures. The next frontal system will
approach the area near the end of the long term period but
appears to have limited moisture to work with at this time.
Above normal temperatures are likely to continue into the
weekend.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
High confidence for restrictions developing tonight and
lingering into Sunday morning.
Nearly stationary front across southern GA this evening will
slowly lift north into SC overnight into Sunday. Guidance
indicating MVFR cigs developing this evening then IFR or LIFR
conditions especially after 08z as frontal boundary moves
slowly north and low-level moisture increases across the region.
The HRRR suggests fog may develop ahead of the front but
confidence not high on development of low visibilities. A few
showers are possible late tonight into Sunday as a weak upper
level disturbance moves across the area.
DNL/AGS...VFR conditions at 00Z lowering to MVFR this evening.
Expect IFR/LIFR ceilings to develop by 08Z as warm front moves
into the area. Visibility restrictions possible toward morning
but confidence low. Ceilings will be slow to rise in the
morning. Have indicated cigs lifting MVFR around 18Z. Scattered
showers possible, but confidence too low to include attm.
EXTENDED AVIATION OUTLOOK...Flight restrictions in stratus and/or
fog expected at times, favoring late night and early morning time
periods, through Tuesday. Widespread showers and thunderstorms
late Monday afternoon and evening.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Charleston SC
1045 PM EDT Sat Apr 6 2019
.SYNOPSIS...
A series of fronts will affect the area through next week. High
pressure will return next weekend.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 1040 PM: I will issue a quick update to maintain a
isolated thunderstorm over the GA waters through midnight.
As of 930 PM: KCLX detected a few light showers over the upper
Wando River area. Elsewhere, a cluster of showers was drifting
east along the lower Altamaha River. I will update the forecast
to lower PoPs to SCHC through the rest of the evening hours.
Isolated showers may linger well into the late night hours. Fog
is expected to become widespread across SE GA after 9Z.
As of 745 PM: KCLX indicated scattered to isolated light showers
to sprinkles over the SC Lowcountry. These showers should fade
over the next 1-2 hours. I will update the forecast to adjust
PoPs and remove the mention of TSRA over the land zones.
Previous Discussion: Through early this evening: There are a
few storms of interest over Long and Tattnall County, in close
proximity to the stationary front, and also where we have a
little better MLCAPE and SR helicity. Conditions favor strong
winds, frequent lightning and heavy rains with these storms,
maybe becoming strong if boundary or cell mergers occur.
Otherwise, widely scattered to scattered showers and a few
Georgia t-storms will occur as a mid level perturbation pulls
off the lower South Carolina and southeast Georgia coast.
Tonight: Convection over the forecast counties and upstream in
southern Georgia will fade with the loss of heating and a short
wave ridge moves overhead. However, with another perturbation
to ripple through, the stationary front to transition into a
warm front that slowly begins to lift north and weak isentropic
ascent on the 295K surfaces, we still expect at least isolated
showers to occur. The front will be situated near the southern
border of the forecast zones this evening, and is currently
forecast to make it near or slightly north of the Savannah River
by daybreak.
While cloud cover will be extensive near and north of the front,
and will be a factor in the development of fog. There will be a
little less coverage of these extensive clouds over Georgia and
also the concern of stratus build down, plus the wet grounds.
This will lead to "patchy" to "areas" of fog after 3 or 4 am,
with the greatest coverage in Georgia where the lowest
condensation pressure deficits are forecast. It is here where we
have the highest potential for a Dense Fog Advisory, as
depicted by the SREF, HRRR, RAP and CONShort guidance.
Temps will be above climo, with most communities 60-63F,
although some upper 50s over parts of the Charleston quad-county
district.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Sunday: A weak front draped across the area around daybreak will
lift north during the morning with a few showers anticipated mainly
over Southeast South Carolina. The axis of a mid/upper lvl ridge of
high pressure will then remain extended over the Southeast United
States, helping temps warm into the upper 70s in northern areas to
lower 80s across much of Southeast Georgia. Temps could even peak
near the mid 80s near the Altamaha River well inland. Given the
amount of sfc heating and low-lvl moisture in place, a slight chance
to chance of showers are possible during the afternoon, especially
for locations away from the coast. A few thunderstorms will also be
possible during peak heating, but will likely remain sub-severe.
Most convection should diminish by late evening with much of the
area remaining dry during the overnight period. Lows will be mild,
only dipping into the low/mid 60s.
Monday: The mid/upper lvl ridge axis will slide offshore, helping
setup a warm southerly flow over the Southeast United States well in
advance of a low pressure system developing over the Mississippi
River Valley. Cloud cover should increase throughout the day, but
persistent warm air advection to the region should allow temps to
peak into the lower 80s for most locations away from the immediate
coast. Sfc heating and low-lvl moisture will once again support a
slight chance to chance of showers during the morning, then greater
coverage during the afternoon as moisture deepens and h5 shortwave
energy traverses over the region. Showers appear likely during peak
heating along with some thunderstorms, but overall severe weather
potential remains low. Showers along with a few thunderstorms could
persist during overnight hours. Lows will remain mild, ranging in
the mid 60s.
Tuesday: A low pressure system over the Deep South is expected to
shift toward the Southeast United States during the afternoon and
evening. Ahead of the system, moisture is expected to deepen with
modest instability under widespread clouds. Showers are likely along
with some thunderstorms, especially during the later half of the day
when SBCAPE approaches 1000-1250 J/kg, PWATs peak around 1.5 inches
and the right-rear quadrant of a 100 kt upper lvl jet promotes
divergence aloft. The bulk of mid-lvl shortwave energy arrives late
along with the sfc low nearing western zones during the evening. Low-
lvl wind fields are not particularly impressive with the system, but
could be sufficient for a few stronger storms capable of gusty
winds before nightfall.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A cold front will cross the area Tuesday night into Wednesday, with
weak high pressure to build in its wake. Relatively quiet weather
expected for Wednesday and Thursday. Next chance of rain will come
late next week when another cold front impacts the area, however at
this time precipitation looks to be in a diminishing state when it
approaches. High pressure is then expected to return over the
weekend. Temperatures generally at or above normal through the
period.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
KCHS: Scattered light showers are forecast to pass near KCHS
through 3Z. I will initialize the KCHS TAF with IFR ceilings,
expecting ceilings to improve to MVFR by 3Z. MOS and forecast
soundings indicate that ceilings will favor MVFR levels through
the rest of the forecast period, limited by a lingering front
over the region.
KSAV: Light winds and lowering ceilings are expected tonight.
The front is forecast to lift north of the terminal late
tonight, becoming favorable to fog development. I will forecast
MVFR fog by 8Z, with periods of dense fog possible between 8Z-
12Z. After sunrise Sunday, IFR ceilings are expected to expand
across KSAV and may remain into the afternoon. The low clouds
with thin and break apart late Sunday afternoon.
Extended Aviation Outlook: Flight restrictions possible at
times into Tuesday, mainly in and near showers and
thunderstorms.
&&
.MARINE...
Tonight: Weak low pressure off the North Carolina coast will
pull east as it reaches around 32N and 70W by daybreak. A cold
front trailing from the low will extend into our far southern
waters early, linking up with a stationary front near the
Altamaha River, before it transitions into a warm front that
will be situated SE to NW near the Savannah River by dawn. Winds
will generally be Easterly at 5-10 kt, and once the evening sea
breeze influences fade, winds will back more NE on the South
Carolina waters and veer a little to the SE on the Georgia
waters. Not much wave energy, mainly 2-3 ft. The risk for fog is
low, although there could be a t-storm or two move into the
AMZ354 waters through 7 or 8 pm.
Sunday through Thursday: Marine conditions are expected to remain
fairly quiet early next week outside of showers and/or thunderstorms
that drift offshore. Southeast winds on Sunday will veer around to
become southerly early next week. Speeds will increase up to 15-20
kt Monday evening into Monday night while seas build up to 3-4 ft,
but conditions are expected to remain below small craft advisory
criteria. A cold front will then cross the waters Tuesday night into
Wednesday with high pressure to return in its wake on Thursday.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...NED
SHORT TERM...
LONG TERM...ETM
AVIATION...NED
MARINE...
Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
835 PM CDT Sat Apr 6 2019
.DISCUSSION...
Little to no activity churning this evening across South Texas so
have trimmed POPs this evening which is the only change made to
the grids. Still looks like the greatest chances for showers and
thunderstorm activity is expected closer to around 06Z and beyond
as a mid- level shortwave swings east out of Mexico. HRRR and
TexasTech models both show this slower trend, with widespread
activity more after 06Z. Cooling in the mid- levels with the
shortwave will lead to steep lapse rates aloft. This combined with
sufficient moisture will support elevated strong to severe storms
with large hail moving out of Mexico into the Rio Grande Plains
and Brush Country toward and after midnight tonight. WRF models
also showing possible bowing segments with farther eastward
movement of activity, suggesting strong damaging winds possible.
Expecting activity to reach the Coastal Plains and Coastal Bend
shortly around daybreak, with activity continuing to push into the
gulf waters through the late morning hours of Sunday.
&&
.PREV DISCUSSION... /Issued 704 PM CDT Sat Apr 6 2019/
DISCUSSION...
Please the aviation discussion below for more details.
AVIATION...
MVFR/IFR conditions will quickly develop this evening across the
Coastal Bend and Victoria area. This will include ALI, CRP, and
VCT. An increasing cap and limited forcing will keep most of
South TX free from organized convection this evening. Still could
see one or two storms originating from Mexico get close to LRD by
midnight but overall will keep the threat for thunderstorms low
this evening. Upstream potent shortwave extending from the AZ/NM
border southward into northern Mexico in association with a jet
max will really begin to develop convection across Mexico later
this evening to several hours past midnight. Excellent agreement
on the various CAM guidance suggests that this cluster of storms
will continue to become better organized with increasing dynamical
forcing and sufficient 0-6 km bulk shear of 40 kt. Will begin the
threat for thunderstorms by 07-08Z for COT and LRD and 10-12Z for
ALI, CRP, and VCT. Will mention the possibility of gusty winds up
to 45-50 kt given the potential for bowing segments to develop.
The complex of storms will end from west to east between 11Z and
18Z as this shortwave moves through the area. Rapid improvement
to VFR conditions will ensue once the heavy rain and thunderstorms
pushes east of the area.
PREV DISCUSSION... /Issued 425 PM CDT Sat Apr 6 2019/
SHORT TERM (Tonight through Sunday Night)...
An upper level long wave trough currently draped along the Rockies
southward across Mexico, is expect to continue slowly moving east.
Embedded short waves will also continue to round the base of the
trough and move northeast across the region tonight through Sunday.
A strong short wave is expected to bring an MCS toward the Rio
Grande Plains this evening. A few storms may develop ahead of this
line through the evening hours, however the stronger, possibly
severe, storms are expected to move into the Rio Grande Plains
between around 11 PM CDT to 1 AM CDT. The system is expected to
reach the coast sometime between 12Z and 15Z and exit the area by
between 18Z to 21Z. A weak frontal bdry associated with this
system, will be the main focus providing low level convergence
for heavier rainfall/strongest storms. Models show strong
diffluence aloft and an unstable airmass ahead of the bdry. The
MCS/surface bdry are expected to exit the region by Sunday
afternoon with drier conditions filtering into S TX.
The primary threat is expected to be large hail and damaging wind. A
few tornadoes may be possible as well. Models show helicity values
of 200-300 developing Sunday morning as the storm system approaches
the coast, thus the tornado threat may increase somewhat Sun
morning.
Heavy rainfall is also possible. Average amounts of 1 to 2 inches
are expected with higher amounts possible. This could lead to
localized flooding, especially across low lying areas. Given the
fairly dry ground and expected steady movement of the system,
widespread flooding is not anticipated at this time.
Dry mid/upper levels and high surface dewpoints and light wind
Sunday night could lead to areas of fog, possibly dense. Some
lingering isolated convection may continue across the eastern
portions of the CWA and over the waters beyond 21Z.
LONG TERM (Monday through Saturday)...
Increasing subsidence/drying Monday as the upper disturbance
continues to move east. The GFS/ECMWF predict an upper ridge to
develop Tuesday over the CNTRL CONUS as another upper disturbance
approaches the West Coast. This upper system is expected to move
across the Plains Wednesday night/Thursday, with the bulk of the
associated synoptic scale lift north of the CWA. Yet, the GFS
predicts an upper jet streak across the CWA/MSA Thursday.
Nevertheless, will only introduce 10% POP values Thursday over
portions of the CWA owing to limited moisture. The GFS/ECMWF
predicts this system to lift NEWD across the Midwest/Great Lakes
while yet another upper system develops across the SRN Rockies/SWRN
CONUS then approaches the CWA Saturday. An upper jet streak Friday,
and additional synoptic scale lift Saturday, along with increasing
moisture in advance of jet/upper system, may result in the
development of convection Friday/Saturday.
MARINE...
Showers and thunderstorms are expected to increase overnight and
Sunday morning then tapering off from west to east late Sunday
afternoon into Sunday night. A weak to moderate southeast flow is
expected tonight then becoming east to northeast Sunday and
northerly Sunday night as a weak frontal bdry moves across the
region. Drying conditions Monday. An upper disturbance will move
across the Plains/TX Wednesday night/Thursday, yet expect moisture
over the MSA to be insufficient for precipitation. Upper level
disturbances Friday and Saturday may result in at least isolated
convection. Sea fog possible Saturday over the bays/nearshore
waters given GFS deterministic surface dew point compared with
likely SST values. However, not yet confident to forecast such.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 70 80 64 86 62 / 70 80 10 10 0
Victoria 68 76 61 83 59 / 70 80 10 10 0
Laredo 68 84 64 90 63 / 80 60 0 0 0
Alice 68 81 63 87 61 / 80 80 10 10 0
Rockport 68 76 65 81 63 / 60 80 10 10 0
Cotulla 64 81 59 87 60 / 80 60 10 0 0
Kingsville 70 83 64 87 61 / 60 80 10 10 0
Navy Corpus 70 77 67 82 65 / 50 80 10 10 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
CB/85...SHORT TERM
Area Forecast Discussion
National Weather Service Dodge City KS
602 PM CDT Sat Apr 6 2019
...Updated aviation discussion...
.SHORT TERM...(This evening through Sunday)
Issued at 106 PM CDT Sat Apr 6 2019
There will be a chance for thunderstorms this afternoon and early
this evening, mainly east and south of Dodge City as an upper
level trough lifts northeast from western Oklahoma into Central
Kansas. A few strong or even severe thunderstorms later this
afternoon can not be ruled out given the forecast instability 1000
to 2000 j/kg and 0-6km shear of 20 to 30 knots at 21Z but does
improve to 30 to 40 knots by 00z Sunday. Currently based on the
RAP the area most favorable for the stronger storms will be east
of a Stafford to Ashland line. Will continue to favor hail up to
the size of quarters given the weak shear at 21z. At 21z is when
the best chances for storms exists in Barber and Pratt counties.
By 00z Sunday the storms should be moving east of highway 281.
As this upper level wave lifts northeast into central Kansas
early this evening the convection east of Dodge City will end from
southwest to northeast. As this area of convection begins to
taper off the focus for early evening/overnight thunderstorms will
then shift east/northeast into eastern Colorado and northwest
Kansas near a surface boundary that will be located ahead of a
weaker upper wave as it exits the central Rockies and approaches
western Kansas. Late day heating along this frontal boundary and
ahead of this next approaching upper wave should give rise to
scattered convection after 21z Saturday just west/northwest of our
county warning area but as these storms develop they will move
east and approach Wakeeney, Scott City and Syracuse by or a little
after 7 pm. Mainly small hail and gusty winds will once again be
the main hazard from some of these stronger storms in our
west/northwest early tonight. The potential exists for hail up to
the size of quarters will be possible before sunset.
On Sunday an area of high pressure will build into western kansas
behind the surface boundary that will be moving across Oklahoma
towards north Texas. Sunday will be warm and dry with highs
climbing into the 70s.
.LONG TERM...(Sunday night through Saturday)
Issued at 106 PM CDT Sat Apr 6 2019
Dry and warm conditions still look on track for the start of the
work week as an upper level ridge weakens as it moves from the
Central Rockies and out into the Plains. Highs will warm into the
75 to 80 degree range on Monday with even a few lower 80s for
highs being possible Tuesday.
The next upper level trough is forecast by the GFS and ECMWF to
cross into the Western High Plain mid week. This will bring our
next decent chance for precipitation to southwest Kansas late
Wednesday. In addition to the next round of precipitation to
southwest Kansas some colder air is also expected to return behind
a cold front. Temperatures behind this mid week cold front will
easily be anywhere from 20 to 25 degrees cooler on Thursday
compared to the high temperatures expected earlier in the week.
Low temperatures Thursday night/Friday morning will range from the
upper 20s to lower 30s.
Highs Thursday are expected to be mainly in the 50s with even a
few upper 40s for highs across portions of north central and west
central Kansas. Temperatures will warm some Friday and early this
weekend but the highs temperatures each day are expected to be
mainly in the 50s to lower 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 602 PM CDT Sat Apr 6 2019
Scattered showers and thunderstorms currently moving through east
and northeast Colorado could impact Hays, and possibly Garden
City, for a few hours this evening. Cigs and vsbys should remain
VFR through tonight although there is some minor potential for
MVFR conditions developing at Hays and Dodge City. By Sunday
morning, winds will be shifting to the northwest across the area
with gusts to around 25-30 knots possible by midday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 74 46 77 / 10 0 0 0
GCK 47 72 44 77 / 20 0 0 0
EHA 46 72 44 76 / 20 10 0 0
LBL 48 74 45 77 / 10 10 0 0
HYS 48 72 47 77 / 30 0 0 0
P28 52 76 49 80 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Burgert
AVIATION...Gerard
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
650 PM CDT Sat Apr 6 2019
.AVIATION...
While a few showers remain south of AUS the bulk of the convection
has moved away from the terminals. This will be the trend through the
evening hours with dry weather expected through 09z along the Rio
Grande and 11z along the I-35 corridor. VFR conditions now will
drop overnight for the I-35 terminals through MVFR to IFR by 07z.
These lower cigs will hang around until the morning round of rain
moves through.
As the main upper trough moves east across Texas another complex of
showers and storms will form late tonight across the Rio Grande
Plains. High resolution models show the complex moving eastward just
south of DRT so have included only VCSH beginning around 09z there.
The complex of showers and storms will approach the I-35 terminals by
11z with a mix of -SHRA and VCTS. While the focus should be moderate
to heavy rainfall a few isolated thunderstorms are possible, so VCTS
was used rather than prevailing TS at this point. The complex of
showers and storms, along with any wrap around precipitation will
move to the east by 15z at DRT and the I-35 terminals by 22z. VFR and
dry conditions will prevail after that with northeast winds less than
10 knots.
&&
.PREV DISCUSSION... /ISSUED 638 PM CDT Sat Apr 6 2019/
UPDATE...
We have allowed the Tornado Watch to expire at 6 PM. An outflow
boundary has pushed east into portions of Fayette, eastern Bastrop
and southern Caldwell counties. The main threat with the remaining
isolated storms west of the outflow boundary will be small hail
through sunset. Re-trended PoPs and temps through the evening hours,
with coverage of convective activity expected to remain isolated.
No changes made to the PoPs and Wx overnight and into Sunday
morning, with the previous forecast package indicating the potential
of an organized complex of storms coming out of Mexico and across
portions of the CWA. We will leave the Flash Flood Watch intact for
the potential of flooding with this second round of storms Sunday.
PREV DISCUSSION... /ISSUED 401 PM CDT Sat Apr 6 2019/
SHORT TERM (Tonight through Sunday Night)...
There remains a small threat for severe weather and tornadoes with no
significant improvements in the near storm airmass until the watch is
set to expire at 6 pm. Some clearing of counties may need to be
considered from the west in the next hour or two however. A tornado
has not be detected or reported in our forecast area today, but a
radar confirmed tornado was noted just north of Williamson County
earlier this afternoon.
A convergent pattern of a lifting warm front over eastern counties
and a re-firing of thunderstorms along an eastward-propagating
outflow boundary from western counties has resulted in locally heavy
downpours of 2 to 4.5 inches over a small area of the eastern Hill
Country and the eastern halves of Travis and Williamson counties.
While much of the area is still waiting on the much anticipated rain
pattern, the areas noted above have already become saturated to the
point of resulting in some significant street flooding and some
waters rising over some low water crossings. Overall, impacts have
been spotty as has been the rains, However, the area between Johnson
City and Taylor extending south to near San Marcos is expected to see
another 1 to 3 inches of rain based on a good portion of the higher
resolution model data for late tonight into midday Sunday.
A few areas south of the FF watch area could see an isolated 4 inch
amounts, but very little rainfall has accumulated thus far outside
of the watch area. With a 90 knot upper jet streak currently diving
south along the Pacific coast of Mexico, the model run to run trends
are deeper and slower with the upper low, which should extend the
residence time of the next round of heavy rains. Much of the HRRR
runs today have shown good consistency on timing and location of
what looks to be a more widespread mcs, which should cover 80 percent
of the forecast area, with only areas NW of a Del Rio to Mountain
Home line possibly missing out on measurable rains. The axis of
heaviest rains with the next system should impact the San Antonio
area from 6 am to 11 am and the Austin area from 7 am to 1 pm. This
heavy rain axis should be along a N-S axis near Hwy 77 by 1 pm with
decreasing chances of run-off producing rains in the early afternoon.
However, the cumulative rains over the Austin metro area could lead
to lingering flood impacts through as late as 3 pm. Additional rain
chances are indicated into Sunday evening, but this should be mostly
spotty rains associated with the elevated rap- around lifting
processes from the middle and upper levels. Further wobbling and
deepening of the upper low could lead to rain chances running into
Monday morning, but these wrap-around rains should be much lighter or
on the order of 1/4 inch or less.
LONG TERM (Monday through Saturday)...
The deeper trough moving over us this weekend will leave a dry regime
and light northerly flow to promote good warming under sunny skies
for Monday. Areas that have received over an inch of rain are likely
to feel some of the effects of Monday afternoon humidities as the
north winds are mostly expected to be less than 10 mph in the
afternoon. Winds are expected to remain light Monday night, but will
not factor in any chances for ground fog until we the rainfall totals
for tonight into Sunday. Sunny and hot conditions develop under
shortwave ridging aloft Tuesday into Wednesday. A few patches of
brief morning clouds may develop Thursday morning with another
mostly sunny and warm day forecast Thursday afternoon when vigorous
upper low passes well to the north of the area. Later forecasts may
need to consider warmer temperatures for Thursday afternoon as
westerly mixing of winds aloft could be a factor. As that upper low
ejects NEwd, another strong low digs into the SWrn US and brings
possibly another good chance of rain for next weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 65 75 59 83 59 / 40 60 20 10 0
Austin Bergstrom Intl Airport 65 74 59 83 58 / 50 70 20 10 0
New Braunfels Muni Airport 65 74 57 84 58 / 60 70 10 10 0
Burnet Muni Airport 63 73 57 81 57 / 30 50 20 10 0
Del Rio Intl Airport 64 84 59 88 61 / 60 20 0 0 0
Georgetown Muni Airport 64 73 59 82 57 / 30 60 30 20 0
Hondo Muni Airport 64 78 57 86 59 / 80 50 10 - 0
San Marcos Muni Airport 65 75 58 83 58 / 60 70 20 10 0
La Grange - Fayette Regional 67 74 60 82 57 / 60 90 40 20 0
San Antonio Intl Airport 65 75 58 85 60 / 70 70 10 10 0
Stinson Muni Airport 65 76 58 85 60 / 80 70 10 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Sunday afternoon for Bastrop-Blanco-
Caldwell-Hays-Lee-Travis-Williamson.
&&
$$
Aviation...Treadway
Short-Term/Long-Term...Runyen
Public Service/Data Collection...EWilliams
Area Forecast Discussion
National Weather Service Hastings NE
637 PM CDT Sat Apr 6 2019
.SHORT TERM...(This evening through Sunday)
Issued at 338 PM CDT Sat Apr 6 2019
Aloft: RAP dynamic tropopause analyses showed fairly zonal flow
over the CONUS. An elongated weak trof was moving thru the Wrn
USA and extended from MT-AZ. A shrtwv trof preceded it from CO-OK.
This trof was lifting NE and will cross KS/NEB tonight.
Meanwhile...the Wrn trof will cont E cross the CWA tomorrow AM
with low-amplitude WNW flow after 17Z.
Surface: A modified continental polar air mass was over the Cntrl
Plns as the rgn was between two fronts. The polar front was
stationary over the Nrn Plns while the subtropical front was
stationary thru the Gulf Coast states to TX. A lee trof was to the
W and extended from MT-NM. This trof will move E acrs the CWA
tonight while part of the front over the Nrn Plns will drop S.
This front will move thru tomorrow AM with very weak high pres
moving over NEB/KS after 17Z.
Rest of this afternoon: temps have climbed into the 70s with
dwpts in the mid-upr 40s. This has resulted in modest instability
with SBCAPE 500-750 J/kg. However...0-6 km shear was very weak
(15-19 kt). Given that this combination will result in only weak
updrafts...we`ll lower potential threats in the HWO down to a max
of dime size hail and G40.
Expect sct shwrs/tstms to cont blossoming this afternoon...mainly
from cntrl KS into Ern NEB...where dwpts are well into the 50s.
The Wrn edge of this activity will probably affect areas E of Hwy
281. Elsewhere...can`t rule out an isolated shwr and possibly some
rumbles of thunder.
Tonight: CAMs cont to indicate a narrow line of sct shwrs/tstms
will form from CBK-MCK-BBW around 00Z. This line is then fcst to
drift E into and acrs parts of the CWA. The 18Z NAM nest suggests
far less shwr/tstm coverage than the 19Z HRRR. That`s why POPs
are pretty low (mainly a chc).
Skies will clear from the W after midnight...mainly W of Hwy 281.
Used consensus of short-term guidance for lows.
Sun: Clearing trend will cont E of Hwy 281 thru mid-mrng...
leaving sunny skies the rest of the day. Could see a few diurnal
stratocu develop. Windy...espcly thru early afternoon. NW winds
will gust up to 35 mph. Used Superblend for highs with a nudge
toward mdl 2m temps. 70-75F.
.LONG TERM...(Sunday night through Saturday)
Issued at 338 PM CDT Sat Apr 6 2019
Pattern: a major pattern change is in the offing. The global mdls
and ensemble means conts to advertise a longwave trof developing
over the Wrn USA. The look over the E Pac will be similar to what
occurred in Feb and early Mar...with a high-over-low config
between AK and HI. That means odds will favor cooler than normal
temps...with a couple days of much colder than normal. Some snow
will be possible as well.
Aloft: Low-amplitude WNW flow will cont into Mon. Tue the ridge
over the Wrn USA will arrive as a deep trof moves in off the Pac.
This is the trof that will initiate the pattern change. It will
advance thru the Wrn USA Tue night and induce lee cyclogenesis
over CO Wed. The low will move acrs NEB Wed night into Thu. As
that low lifts into the upr Midwest Fri...another low will dive
down the W coast into the Desert SW. Heights will rise here as a
shrtwv ridge moves over the CWA Fri-Sat...but that next low will
be on our doorstep by Sat.
Surface: A weak low and cool front will come out of the Nrn Rckys
Sun night and cross the CWA Mon. This front will become
stationary acrs from the NEB panhandle SE acrs KS Tue. The thermal
gradient along this front will tighten as lee cyclogenesis occurs
over CO Tue. There are minor diffs in where this low tracks acrs
NEB or KS Wed that have tremendous impacts on the fcst.
Interestingly...the GFS/EC tracks have flipped compared to prvs
days. The GFS runs are now over NEB while the last 2 EC runs are
over KS. That could make the diff btwn highs in the 70s/80s Wed or
highs in the 40s over parts of the CWA. The CWA will be in the
cold sector Thu as this low moves away. Weak high pres should
briefly move overhead Fri and possibly linger into Sat.
Temps: Much warmer than normal Mon-Tue with widespread 70s with
low 80s from Cambridge-Plainville. Wed-Fri do not take our fcst
verbatim. There is significant mdl uncertainty. What you are
seeing is a blend of multiple mdls with vastly differing
solutions. It is almost a certainty that Thu-Sat will be much
colder than what we are advertising...espcly if/where any snow
accumulates.
Precip: We know a big/deep low will be moving thru Wed-Thu...but
with all the mdl uncertainty on its future location...it`s
difficult to provide much detail that`s worth anything. For now we
can provide possible scenarios:
1) There will probably be no shwr/tstm activity in the warm
sector. This system will advect a significant cap/EML from the
Desert SW. All of the precip with this system (at least while it`s
over the Plns) will be on the cold side of the warm and cold
fronts.
2) Light rain (and more likely drzl) will struggle to form over
S-cntrl NEB Wed while a raging blzd will be on-going from the
Sandhills back into the NEB panhandle. This area of deformation
hvy snow would then move into the CWA Wed night into Thu...with
blzd conds probable. This scenario would result in some parts of
the CWA measuring svrl inches of snow with significant drifting
and severe blowing snow.
3) Sct shwrs/tstms develop Wed eve with steady rain/snow moving
in from Wrn NEB and NW KS Wed night into Thu. Most likely any
rain would change to snow. Can`t rule out just snow moving in.
This too could result in accumulating snow.
These are preliminary thoughts and they could be significantly
altered. There are probably other scenarios not mentioned.
Other things we will need to watch...
Wind: There is potential for high winds (sustained around 40 mph
with gusts at or above 58 mph).
Fire Wx: If the warmer/more N GFS scenario unfolds...can envision
Red Flag Warnings being needed. We will need to check on status of
fuels.
Severe tstms: can`t be completely ruled out in the further N
scenario...but we would still be dealing with a significant cap
that could mitigate the risk of svr tstms.
Needless to say...there is potential for multiple hazards with
this mid-wk storm. Cont to closely monitor fcsts and be prepared
to take any necessary precautions.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday)
Issued at 630 PM CDT Sat Apr 6 2019
VFR conditions are expected through the period but there will be a
chance for a -TSRA through much of the overnight hours...with
strong northwesterly winds developing across the local area after
daybreak Sunday.
This evening...expect a line of showers and thunderstorms to
develop west of the terminals...slowly tracking each and reaching
KEAR by around 07/03Z. These should dissipate by the very late
overnight hours...with skies beginning to clear behind the
associated front around daybreak. Thereafter winds will increase
behind the front...gusting to near 30KTS out of the northwest for
much of the late morning through early afternoon hours.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
SHORT TERM...Kelley
LONG TERM...Kelley
AVIATION...Rossi
Area Forecast Discussion
National Weather Service Lincoln IL
815 PM CDT Sat Apr 6 2019
.UPDATE...
Issued at 815 PM CDT Sat Apr 6 2019
Evening balloon sounding shows a fairly dry atmosphere over
central Illinois this evening. Showers are edging into far
southern Missouri, but the bulk of the convection is currently
across eastern Kansas and Nebraska. Dry conditions expected to
prevail over our area the remainder of the evening, with most of
the rain beginning to move in after about 2 am. High-res models
are generally focusing on a 3-4 hour period of showers and
isolated thunderstorms as the warm front moves into the area,
though the latest RAP shows a more widespread rain south of I-70
much of Sunday morning. Forecast was mainly tweaked for the latest
PoP trends, with only minor updates to the temperatures over the
next few hours.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 355 PM CDT Sat Apr 6 2019
1024 mb high pressure over the eastern Great Lakes and mid
Atlantic States, was providing a nice early spring afternoon
across central and southeast IL. Partly to mostly sunny skies
prevailed, with scattered fair weather cumulus clouds along and
east of the IL river. Southeast winds of 5-15 mph and a few gusts
around 20 mph. Mild temperatures of 65-70F at mid afternoon with
Flora, Lawrenceville, Paris and Pittsfield the warm spots at 70F.
An upper level trof moving into the central plains will track
across MO/IL during overnight, spreading showers and isolated
thunderstorms ne across CWA. 12Z models continue to trend slower
with arrival of this band of convection overnight, and may not
reach areas ne of I-74 until daybreak. Lows overnight in the low
to mid 50s, coolest along and ne of I-74.
Chance of showers and isolated thunderstorms to diminish from sw
to ne during mid/late Sunday morning and to get into a lull during
part of the day Sunday as warm front lifts nne of CWA by late
Sunday morning. Breezy sw winds along with some peaks of sunshine
Sunday afternoon to warm temps into the 70-75F range. A cold front
to push east into central IL late Sunday afternoon/early Sunday
evening and could develop some scattered showers/thunderstorms.
SPC day2 outlook continues slight risk of severe storms over
southern 6 counties with marginal risk as far nw as a Winchester
to Lincoln to Gibson City line. Models show 25-35 kts bulk shear,
weak lift and some instability with CAPES peaking from 1000-2000
j/kg in southern CWA. This supports marginal to slight risk from
21Z/4 pm Sunday into early Sunday evening.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 355 PM CDT Sat Apr 6 2019
Chances of showers to linger in southeast IL overnight Sunday
night and Monday morning as weak cold front then pushes toward
the Ohio river valley into southeast IL. Models continue to trend
warmer on Monday even behind weak front with highs mostly in the
mid 70s and some guidance like MAV showing upper 70s over a few
our or cities in our CWA. Winds look fairly light on Monday and
ample sunshine over central IL, with partly to mostly cloudy skies
near front in southeast IL and isolated light rain showers
possible.
Dry and mild weather prevailed Monday night thru Tue night across
the area with highs Tue in the upper 60s and lower 70s, warmest in
southeast IL. 12Z models have trended further north with warm air
advection driven showers over areas from I-74 north later Tue
night into Wed, and shifts mainly north of much of CWA Wed
afternoon and wed night. Highs Wed range from lower 60s from I-74
ne and upper 60s to near 70F sw CWA and se IL.
Models have gotten even stronger with a strong storm system
ejecting out of central Rockies into the central plains by 18Z/Thu
and bringing a cold front east across IL Thu evening. This will
like bring another round of showers and some thunderstorms Thu and
Thu evening. One more mild day Thu with highs in the low to mid
60s over IL river valley and 70-75F over southeast IL. A few
thunderstorms could get strong late Thu afternoon into Thu evening
with very strong dynamics of this storm system. Isolated light
showers possible over east central IL fri morning, and getting
much colder on back side of storm system. Highs Fri range form low
to mid 50s over IL river valley and lower 60s in southeast IL.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 615 PM CDT Sat Apr 6 2019
VFR conditions expected to prevail through about 09Z. After that,
a band of rain will move northeast, and ceilings expected to
quickly deteriorate below 2,000 feet. A few hours of IFR
conditions are expected Sunday morning, before ceilings slowly
climb again.
Southeast winds will trend more to the south/southwest early
Sunday, following passage of a warm front, and increase to 10-15
knots. Late in the period, a cold front will cross central
Illinois, with winds turning to the west.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...07
LONG TERM...07
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Nashville TN
842 PM CDT Sat Apr 6 2019
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
At update time, nothing is going on in Middle TN other than
increasing cloud cover. However, we continue to watch to the
southwest as showers and thunderstorms have moved from central MS
into northern Alabama, towards the mid-state. Latest RAP continues
to show improving conditions for thunderstorm development after
midnight, with 500-1000 J/Kg CAPE and 35-40 kts of effective bulk
shear pushing into Middle TN counties south of I-40. I feel this
might be a little bullish based on the latest HRRR guidance
showing only showers the rest of the night. Will keep a mention of
thunder through 12Z, but as better dynamics aren`t expected until
mid-morning Sunday, this might even be overkill.
Speaking of Sunday, we`re still watching the potential for strong
to severe thunderstorms across the northwest half of Middle TN.
Latest guidance still suggests this could be possible as early as
the mid to late morning hours, and persist into the early evening
hours due to a couple different waves of activity. Strong damaging
winds and hail continue to be the main concerns as 7-8 degree/km
mid-level lapse rates are still being shown in forecast soundings.
Needless to say, this isn`t likely to be a widespread severe
event, but if you have outdoor plans tomorrow, it`ll be necessary
to remain weather aware throughout the day.
&&
.AVIATION...
00Z TAF DISCUSSION.
KBNA/KMQY/KCKV/KCSV...We start the evening VFR, but an approaching
swath of isentropically lifted air from the southwest will help
spread showers and a few storms into Middle Tennessee later
tonight and Sunday morning. The HRRR brings a convective complex
across the mid state after midnight, and have timed the overnight
weather using this short- range model. Look for ceilings to drop
to MVFR by 12Z Sunday as winds increase from the south.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......Unger
AVIATION........08
Area Forecast Discussion
National Weather Service Spokane WA
554 PM PDT Sat Apr 6 2019
.SYNOPSIS...
The remainder of the weekend into Monday will be wet with the most
significant rainfall occurring over southeast Washington as well
as the central and southern Idaho Panhandle. Rises are expected on
small streams and rivers including the Saint Joe, Coeur d`Alene,
Palouse, and Grand Ronde Rivers. Precipitation is expected to
decrease to showers Tuesday with unsettled and showery conditions
for much of next week.
&&
.DISCUSSION...
Minor update to adjust evening POP`s and sky cover based on radar
trends. Also removed the early evening slight chance of
thunderstorms except for a small area between Sandpoint and Coeur
d`Alene where a band of showers could produce a stray lightning
strike. See previous discussion below for more forecast details.
&&
.AVIATION...
00z TAFS: Drier air is moving into the region behind the weather
system that brought rain earlier. Still a few lingering MVFR CIGS
at KGEG/KSFF/KCOE but these should become VFR by 01z. The next
weather system will spread rain and lowering CIGS into the region
overnight into early Sunday morning before shifting to the south.
MVFR conditions will be common over Eastern WA into the Idaho
Panhandle with localized IFR conditions possible. JW
&&
.PREV DISCUSSION... /issued 451 PM PDT Sat Apr 6 2019/
Tonight through Sunday night: Water vapor satellite imagery this
afternoon shows a shortwave disturbance moving across eastern WA.
A -28 C cold pool aloft at 500 mbs will help to destabilize the
atmosphere. Convection through this evening is expected to be less
widespread than what was observed yesterday afternoon as synoptic
scale lift will be absent along the backside of this wave. The
RUC and NAM models indicate the potential for 500 J/kg of CAPE
into the late afternoon across the Palouse, but such a strong
shear profile with around 70 kts of wind at 500 mbs will probably
knock the tops off any convection as it tries to get going. Look
for showers to die quickly through the evening.
The next weather system will then quickly move up into the region
along a warm front with good isentropic ascent in the warm sector.
The trickiest part with this system will be snow levels in the
east slopes of the northern Cascades. Some clearing this evening
will allow temperatures to cool off near to or below freezing.
Precipitaiton will begin overnight at the coldest time of the day,
so expect some snow to fall around Plain and possibly in and
around Leavenworth. This will also be the case in the Methow
Valley and at Republic. Accumulating snow may be restricted to
non road surfaces, but a different story for the passes including
Blewett, Stevens, Loup Loup, Sherman and Washington Pass along the
North Cascade Highway. I am expecting slushy accumulations over
these passes with slick travel possible. Doesn`t appear to be
enough snow to warrant a snow advisory but will need to be
monitored. Otherwise, we are looking for widespread valley rain
and mountain snow through Sunday morning. Models have trended
drier in the lee of the Cascades Sunday afternoon with the cold
front pushing in. Precipitation chances were dropped considerably
as such.
The area that stands to receive a considerable amount of
rainfall would be over the southeast portion of the region. The
cold front looks to get hung up from northeast OR to the southern-
central ID Panhandle. Precipitaiton will continue to fall across
these areas through Sunday night with between a half and three-
quarters of an inch of rainfall possible for Pullman, the L-C
Valley and into St. Maries and the Silver Valley. The Camas
Prairie will see around an inch and a quarter and could be as
much as a couple inches if the wetter GFS solution verifies. The
added rainfall will result in rises to small streams and rivers.
Rock slides and mud flows will be possible, especially in steeper
terrain. /SVH
Monday through Thursday...A fast moving upper short wave will push
east across the PAC Northwest with weak ridging building only
briefly over the region by late Monday into Tuesday morning. This
upper short wave disturbance, however, will still have sufficient
moisture to increase chances of shower activity over mostly the
southeastern Washington zones along with central Panhandle region.
The next upstream disturbance will split with most of the
significant energy again being directly south across the Columbia
Basin, L-C Valley, and Camas Prairie which should see a modest
increase in PoPs across those areas. Model guidance mostly concurs
with this assessment with the Canadian guidance showing less
moisture transport than either the GFS or ECMWF guidance. In
addition, enough of the cold core along with good upper vorticity
should remain around Tuesday afternoon to destabilize the
atmosphere and support late afternoon thunderstorms for the Idaho
Panhandle mountains. There will be another brief break in the
action late Tuesday night and early Wednesday, but another upper
short wave disturbance will again possibly begin to affect the
region by midday through afternoon Wednesday. Moisture associated
with this wave will mostly increase the chance of POPs over the
extreme eastern areas of Washington with the greater affect felt
across the central Idaho Panhandle region. The result will be a
chance for light showers developing across the regional mountains
Wednesday and continuing to a lesser extent Thursday morning.
Also, temperatures will range from the mid 50s to low 60s which
will only be slightly above normal for this spring-time period.
/aky
Thursday through Saturday: The western two-thirds of the United
States is expected to be under the influence of a longwave low
pressure trough on Thursday. As one deep low brings the potential
for a late season snowstorm to the Dakotas another trough moving
into the Pacific Northwest will bring rain and snow showers to our
region. Look for snow levels to be as low as 2500ft Thursday
morning before rising into the 3500 to 4000ft range with scattered
showers in the afternoon. There are model differences on the
track of the incoming low Thursday, but it looks like there will
be enough cold air aloft for the mention of a slight chance of
thunderstorms in northeast Washington and north Idaho. A blend of
the models suggests that there will be chances for lingering
showers over the mountainous terrain Friday. Keep your fingers
crossed that a transient upper level ridge will set up long enough
into Saturday for some dry weather to start next weekend. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 53 43 58 37 57 / 80 80 50 30 30 40
Coeur d`Alene 37 52 40 56 37 54 / 70 80 60 40 30 50
Pullman 40 53 44 55 38 51 / 90 90 90 40 40 50
Lewiston 44 62 49 62 44 57 / 70 90 80 50 40 50
Colville 35 56 34 56 30 56 / 40 80 20 30 20 20
Sandpoint 35 49 37 57 35 54 / 60 80 40 50 30 40
Kellogg 36 49 41 52 38 51 / 60 90 80 60 40 50
Moses Lake 41 60 43 63 38 63 / 90 80 50 20 20 20
Wenatchee 38 57 40 58 39 59 / 90 80 40 20 30 10
Omak 36 58 39 58 36 60 / 30 70 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Paducah KY
1001 PM CDT Sat Apr 6 2019
.UPDATE...
Issued at 1001 PM CDT Sat Apr 6 2019
Made some adjustments to PoP, weather, and QPF for the rest of
tonight and the daytime hours on Sunday. Added a mention of
"gusty" winds to part of the WFO PAH forecast area after 3am CDT
through 7 am CDT, mainly over parts of southeast Missouri and the
Purchase area of west Kentucky to reflect the threat of higher
wind gusts. The stronger wind gusts translate over to parts of
southeast Illinois, west Kentucky, and southwest Indiana through
the morning hours on Sunday.
Given the broad slight risk area depicted by the Storm Prediction
Center for Sunday, was not confident enough to make a distinct
severe wording mention at this time at any one location with this
update.
Looking the the 00z/01z Sunday RAP and 18z Saturday/00z Sunday
12km NAM guidance, there is some concern that the 0-3km
contribution of bulk shear (35-45 knots), localized 200-400 m2/s3
surface helicity, overturning of drier air aloft from the
northwest, as well as some MUCAPE expenditure could lead to some
robust rotating updrafts leading to strong thunderstorm (severe?)
development in southern sections of southeast Missouri around or
shortly after 12z (7 am CDT) Sunday, rapidly translating toward
southeast Illinois, southwest Indiana, and northwest Kentucky
between 10 am CDT to 1 pm CDT.
The RAP/NAM guidance are strongly suggestive of drier air aloft
descending into western sections of the WFO PAH forecast area
during the afternoon hours on Sunday, limiting the depth of deep
layer moisture. At this time, not confident enough to totally
eliminate PoPs in this area, so kept with the trend of lowered
PoPs depicted by the dayshift short term forecaster.
The main potential for enhanced wind gusts will likely shift
toward the Pennyrile region of west Kentucky by the middle and
late afternoon hours.
UPDATE Issued at 603 PM CDT Sat Apr 6 2019
For aviation section only.
&&
.SHORT TERM...(Tonight through Monday night)
Issued at 303 PM CDT Sat Apr 6 2019
Early this afternoon, high pressure was across the eastern U.S.,
with low pressure over the High Plains of the central U.S. An
energetic s/wv aloft was lifting northeast into the central Plains,
with a second wave, perhaps convectively induced over the Red River
Valley region. Expect a quiet early evening. Then our focus turns to
the aforementioned wave to our southwest. It is forecast to move
northeast and across the region tonight. Expect some showers and a
few thunderstorms, generally from 03-04z SEMO, to 08-10z up across
the KEVV tristate as the activity moves northeast. After the passage
of this wave, there may be a brief lull, but the models continue to
show some mid level support for additional showers and storms Sunday
morning.
Convection, and any severe weather possibility is highly conditional
Sunday. The CAM`s data gets the gist of what`s going on...the wave
tonight, then a regeneration of convection Sunday morning through
midday. The activity should be more focused over west KY by Sunday
afternoon, possibly dropping off in coverage or ending for a time up
across southern IL into southwest IN and parts of SEMO. The NAM
suggests too much ongoing convection will be a hindrance to good
destabilization Sunday. The GFS is more unstable and across more of
the area. Tend to think without much if any capping, and the
presence of mid level support, it will not take long for convection
to get going again, increasing clouds and possibly limiting further
destabilization. Overall, seems like a marginal severe risk, with
the best chance of severe over west KY where there should be
slightly better 0-3km bulk shear juxtaposed with slightly better
instability.
The lull will continue Sunday evening, then activity picks back up
after 06z Sunday night, as a secondary southern stream H5 low heads
east across the southern U.S. resulting in an uptick in moisture for
showers and maybe storms over our southeast counties, primarily west
KY. The chance will taper off Monday from west to east as the wave
moves away from the area.
It will be warm and somewhat humid through the period with little
change in airmass expected, once we get in the more humid air
tonight as a warm front lifts north across the area. Went with
persistence, MOS and model output for temps.
.LONG TERM...(Tuesday through Saturday)
Issued at 303 PM CDT Sat Apr 6 2019
The primary forecast concern in the long term is the potential for
showers and thunderstorms Thursday and Thursday night, in addition
to windy conditions, with the approach and passage of a low pressure
system and its associated cold front. Fairly good model agreement
lends higher than average confidence to the forecast through Friday.
Confidence drops off by next weekend with greater model variability.
Starting with Tuesday morning, a ridge of high pressure is forecast
to be centered along the range of the Rocky Mountains with split
northern and southern stream troughs over the eastern U.S. The ridge
is forecast to build east through mid week, resulting in dry weather
through Thursday morning.
Southerly winds will begin to pick up on Wednesday and especially
Thursday as a low pressure system develops over the Central Plains
and moves east towards the Mississippi Valley. Winds on Thursday
will be quite strong, sustained 20 to 25 mph with gusts of 30 to 40
mph at times.
The combination of forcing for ascent and increasing Gulf moisture
will lead to a chance of showers by Thursday afternoon and evening.
Thunderstorms will also be possible given the projected availability
of surface based instability. Given the magnitude of forecast wind
profiles, a few strong storms are not out of the question.
Dry weather should return by Friday in the wake of the cold front.
Models have shown some divergence heading into the weekend, but the
12Z ECMWF is admittedly fairly close to the GFS and CMC. Shortwave
energy over the southwestern U.S. is forecast to eject east across
the southern Plains, resulting in an increasing chance of showers,
especially by the latter half of the weekend. At this time, the
current forecast includes a small chance of showers on Saturday,
mainly influenced by the faster 00Z ECMWF.
Temperatures will start off warmer than normal with highs in the mid
to upper 70s Tuesday through Thursday, dropping back into the 60s
Friday and Saturday. Lows should rise from around 50 Tuesday night
to near 60 Wednesday night, then drop back into the 40s by Friday
night.
&&
.AVIATION...
Issued at 605 PM CDT Sat Apr 6 2019
Tonight, there will be a chance of showers and storms mainly
after midnight, with VFR cigs possibly lowering to MVFR after 06z.
The chance of showers and a few storms will continue Sunday low
VFR to high MVFR cigs the rule. Brief IFR cigs and MVFR/IFR vsbys
likely in heavier showers and storms, scattered across the area.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...Smith
SHORT TERM...08
LONG TERM...RJP
Area Forecast Discussion
National Weather Service Blacksburg VA
1125 PM EDT Sat Apr 6 2019
.SYNOPSIS...
Weak ridge of high pressure will remain anchored over the
Tidewater Virginia area through tonight. A low pressure system
over the north-central Plains tonight will move east into the
Great Lakes on Sunday then will bring a cold front through the
region Tuesday. Then the next storm system from the central
United States will impact the east on Friday.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 1124 PM EDT Saturday...
Update to account for cooler temperatures given better radiative
cooling as skies have cleared. Winds are expected to remain
light east to southeast across eastern parts of the forecast
area under weak ridge of high pressure. With dewpoints even
higher than last night, this will again favor potential patchy
mist or fog with intervals of low clouds as well. Visby progs
from the GFS LAMP guidance as well as the HRRR and NAM-3km each
show this fog potential well in the Piedmont and foothills
areas, with more mixed signals in the New and southern
Shenandoah River Valleys. Will introduce a greater fog coverage
areawide which should last into early Sunday morning. Otherwise,
forecast appears to be on track.
Previous discussion from this afternoon...
High pressure will slide east and northeast tonight into Sunday.
Meanwhile, a warm front lifts northeast from the Gulf Coast states
across Virginia during the day Sunday.
Tonight, aside from some pockets of light rain along the Blue Ridge,
look for skies to fill back in with stratus due to low level
inversion. Most will be cloudy Sunday morning at dawn, with
patchy fog around. Temps will be above normal by about 5 to 12
degrees, with lows in the lower to mid 50s.
Sunday will be mild again. Instability appears a little more limited
until later in the day after the warm front moves across due the
cloud cover. Best lift and instability look to move across the TN
Valley into the southern Ohio Valley. Nonetheless, expect some
thunderstorms to make it toward far SW VA/southern WV and NW NC
by late afternoon, with best chance/coverage of showers west of the
Blue Ridge with less threat in the Piedmont.
Highs to range from the mid 60 to around 70 along/west of the Blue
Ridge, to lower to mid 70s in the Piedmont.
Forecast confidence in temps and winds is high, but medium/average
on clouds and thunderstorms.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 330 PM EDT Saturday...
Sunday night into early Monday, a shortwave trough will progress
eastward through the eastern Great Lakes region. Concurrently,
a stronger closed low over eastern Texas will be making slow
progression towards the Arklatex region. Light isolated to
scattered showers are still forecast Sunday night into early
Monday in association mainly with a good moisture fetch into the
area, and upper level support from the northern stream
shortwave trough. Once we progress into Monday night, while the
moisture feed continues, upper level support will transfer to
that provided by the slow moving closed low that will be near
the MS/AL border around daybreak Monday.
From Monday through Tuesday, the model solutions have trended
with a farther south track of the southern stream upper low.
For our region, this should mean that the best instability
should be positioned farther south of the forecast area, but not
displaced so much as to preclude any thunderstorm activity. We
will continue to have very good coverage of showers during this
time period, but with the best thunderstorm potential generally
along and south of Route 460, with much less coverage north of
this area.
Temperatures during the Monday and Tuesday portion of the forecast
will average about 10 degrees above normal.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 330 PM EDT Saturday...
An upper level shortwave ridge of high pressure will settle
over the region Wednesday into Wednesday night. This feature,
and high pressure at the surface, will provide the region with
dry weather and temperatures around five to ten degrees above
normal.
Expect Thursday to be a day of transition. The surface ridge
and surface high will be shunted eastward in response to an
approaching upper level low across the Central Plains states.
Flow between this departing high and approaching low will
slowly veer south as Thursday progresses and increase in speed
to near 30 to 40 kts at 850mb. The origins of the air being
advected into the area will be from the Atlantic, just off the
coast of the Carolinas. As this moisture butts up against the
higher terrain of the Blue Ridge, isolated to scattered showers
will be possible late in the day Thursday across parts of the
Northern Mountains and Foothills of North Carolina.
Thursday night we are expecting the coverage of upslope showers
to advance northeastward along the crest of the Blue Ridge.
Additionally, the approach of the upper level low and its
associated trough will allow for isolated to scattered coverage
of showers across much of the rest of the forecast area by
daybreak Friday, with the best coverage across southeast West
Virginia.
For Friday, model guidance is in better agreement than their
counterpart solutions of 24 hours prior. Confidence has
increased for there to be a significant coverage of showers
across the region in advance of the upper low`s associated
trough axis and surface cold front. Winds at 850mb are forecast
to continue increase in speed, 40 to 45 kts, and continue
veering to more a southwest direction. With the GFS offering
0-1km shear of 30kts, Showalter values between -3 and -2 C, and
SB-VIs as low as -3 to -2 C, and SBCAPE around 400-600 J/Kg,
will continue with the mention of isolated thunderstorms for at
least the entire forecast area around mid-day. By the late
afternoon, additional storms more likely will be focus across
the southeastern portion of the area and perhaps increase in
coverage to scattered, before trending to isolated again by
sunset.
Friday night into Saturday, model guidance has trended slower
with the departure of the cold front and lingering isolated
showers in its wake. Will reflect this with a slight chance of
showers across primarily the southeastern sections of the area
during this time period.
Temperatures across the area Thursday into Friday will continue
to be around five to ten degrees above normal. In the wake of
the cold front, readings on Saturday will be more in line with
values around five degrees above normal.
Confidence in this portion of the forecast is moderate.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
As of 750 PM EDT Saturday...
TAF sites will start the period with VFR conditions. However as high
pressure continues to slide off to our east, southeasterly winds
will pool low level moisture along and east of the Blue Ridge,
developing IFR CIGs as well as some fog overnight. Flight conditions
will trend upward a bit Sunday as a warm front moves up from the
southwest and brings some showers and possibly thunderstorms to the
Appalachians. The best forcing will slide by to our northwest and
keep the best chance of showers/thunder west of the Blue Ridge, so
will confine mention thunder to KBLF and KLWB.
EXTENDED AVIATION DISCUSSION...
MVFR/IFR conditions are possible with scattered showers and isolated
thunderstorms through Tuesday. Drier weather and VFR ceilings and
visibilities are expected Wednesday into Wednesday night.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AL/AMS
NEAR TERM...AL/WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...MBS
EQUIPMENT...AMS
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
749 PM EDT Sat Apr 6 2019
.UPDATE...
We saw a couple of moderate storms this afternoon along the Nature
Coast and inland areas of Polk County with some gusty winds
around 25 knots and dime sized hail reported. These were
short lived and did not meet any severe weather criteria.
The radar is quieting down this evening with only a couple
of storms over the northern part of Polk County. HRRR
guidance has all storm activity dying down over the next
couple of hours with a quiet night expected. Temperatures
topped out in the middle 80`s for most of the area which was
around 5-7 degrees above average. A warm night is expected
tonight with another hot day on tap for tomorrow. Adjusted
the POPs down for tonight based on latest radar imagery and
model guidance. No other changes needed at this time.
&&
.AVIATION...
VFR conditions are expected to hold through the period. Winds will
be light and variable overnight, then increasing east-southeast at
10 knots or less during the day on Sunday. No other aviation impacts
expected.
&&
.MARINE...
Some sea fog possible tonight north of Tarpon Springs. Otherwise
high pressure north of the waters will keep predominantly east-
southeast flow over the waters through the first half of Monday,
then winds turn onshore for the rest of the period. No headlines
expected as winds remain 15 knots or less. Periods of showers and
thunderstorms possible Monday and Tuesday, followed by improving
conditions on Wednesday.
&&
.Preliminary Point Temps/PoPs...
TPA 71 87 72 85 / 10 10 0 30
FMY 70 89 70 88 / 0 30 0 20
GIF 69 89 70 89 / 20 0 0 50
SRQ 68 85 69 84 / 10 10 0 20
BKV 64 88 66 87 / 10 10 0 40
SPG 72 86 73 85 / 10 10 0 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...None.
Gulf waters...None.
&&
$$
UPDATE/AVIATION/MARINE...74/Wynn
DECISION SUPPORT...25/Davis